Synthesis and characterization of fructosyltransferase from Aspergillus oryzae ipt-301 for high fructooligosaccharides production

Fructooligosaccharides (FOS) are mainly produced by microbial fructosyltransferases (FTase, E.C.2.4.1.9), and Aspergillus oryzae IPT-301 has shown high fructosyl transferring and low hydrolytic activities, which leads to high FOS production yields, but the main operating parameters for its best performance have been scarcely studied. Thus, this work aimed to evaluate the cellular growth, production and characterization of mycelial and extracellular FTases by Aspergillus oryzae IPT-301. Experimental design showed that the extracellular FTase performance was optimized (high transfructosylation activity and low hydrolytic activity) for reaction pH 5.5 - 6.75 and temperature of 45-50 °C and was fitted by the Michaelis-Menten model, while the mycelial FTase showed better performance at pH below 6.5 and temperature above 46 °C and was better fitted by the Hill model. The results obtained showed that the fungus represents a promising source for FOS production on a laboratorial scale.The authors gratefully acknowledge The State of Minas Gerais Research Foundation (FAPEMIG, Process APQ-02131-14) for providing financial support and the Institute for Technological Research (IPT/SP)/Programa Novos Talentos, through an individual research grant attributed to Cristiane Angélica Ottoni.info:eu-repo/semantics/publishedVersio

Soil and Rhizosphere Associated Fungi in Gray Mangroves (Avicennia marina) from the Red Sea — A Metagenomic Approach

Covering a quarter of the world’s tropical coastlines and being one of the most threatened ecosystems, mangroves are among the major sources of terrestrial organic matter to oceans and harbor a wide microbial diversity. In order to protect, restore, and better understand these ecosystems, researchers have extensively studied their microbiology, yet few surveys have focused on their fungal communities. Our lack of knowledge is even more pronounced for specific fungal populations, such as the ones associated with the rhizosphere. Likewise, the Red Sea gray mangroves (Avicennia marina) remain poorly characterized, and understanding of their fungal communities still relies on cultivation-dependent methods. In this study, we analyzed metagenomic datasets from gray mangrove rhizosphere and bulk soil samples collected in the Red Sea coast, to obtain a snapshot of their fungal communities. Our data indicated that Ascomycota was the dominant phylum (76%–85%), while Basidiomycota was less abundant (14%–24%), yet present in higher numbers than usually reported for such environments. Fungal communities were more stable within the rhizosphere than within the bulk soil, both at class and genus level. This finding is consistent with the intrinsic patchiness in soil sediments and with the selection of specific microbial communities by plant roots. Our study indicates the presence of several species on this mycobiome that were not previously reported as mangrove-associated. In particular, we detected representatives of several commercially-used fungi, e.g., producers of secreted cellulases and anaerobic producers of cellulosomes. These results represent additional insights into the fungal community of the gray mangroves of the Red Sea, and show that they are significantly richer than previously reported

Terrestrial behavior in titi monkeys (Callicebus, Cheracebus, and Plecturocebus) : potential correlates, patterns, and differences between genera

For arboreal primates, ground use may increase dispersal opportunities, tolerance to habitat change, access to ground-based resources, and resilience to human disturbances, and so has conservation implications. We collated published and unpublished data from 86 studies across 65 localities to assess titi monkey (Callicebinae) terrestriality. We examined whether the frequency of terrestrial activity correlated with study duration (a proxy for sampling effort), rainfall level (a proxy for food availability seasonality), and forest height (a proxy for vertical niche dimension). Terrestrial activity was recorded frequently for Callicebus and Plecturocebus spp., but rarely for Cheracebus spp. Terrestrial resting, anti-predator behavior, geophagy, and playing frequencies in Callicebus and Plecturocebus spp., but feeding and moving differed. Callicebus spp. often ate or searched for new leaves terrestrially. Plecturocebus spp. descended primarily to ingest terrestrial invertebrates and soil. Study duration correlated positively and rainfall level negatively with terrestrial activity. Though differences in sampling effort and methods limited comparisons and interpretation, overall, titi monkeys commonly engaged in a variety of terrestrial activities. Terrestrial behavior in Callicebus and Plecturocebus capacities may bolster resistance to habitat fragmentation. However, it is uncertain if the low frequency of terrestriality recorded for Cheracebus spp. is a genus-specific trait associated with a more basal phylogenetic position, or because studies of this genus occurred in pristine habitats. Observations of terrestrial behavior increased with increasing sampling effort and decreasing food availability. Overall, we found a high frequency of terrestrial behavior in titi monkeys, unlike that observed in other pitheciids

Biosynthesis of silver nanoparticles using actinomycetes, phytotoxicity on rice seeds, and potential application in the biocontrol of phytopathogens

To find effective silver nanoparticles (AgNPs) for control of phytopathogens, inthis study, two strains of actinomycetes isolated from the soil of the Brazilianbiome Caatinga (Caat5–35) and from mangrove sediment (Canv1–58) wereutilized. The strains were identified by using the 16S rRNA gene sequencing asStreptomycessp., related toStreptomyces mimosusspecies. The obtained AgNPswere coded as AgNPs35and AgNPs58and characterized by size andmorphology using dynamic light scattering, zeta potential, transmissionelectron microscopy, and Fourier transformed infrared (FTIR). The antifungalactivity of the AgNPs35and AgNPs58was evaluatedin vitroby the minimalinhibitory concentration (MIC) assay on the phytopathogens,Alternariasolani,Alternaria alternata, andColletotrichum gloeosporioides. The phytotoxiceffect was evaluated by the germination rate and seedling growth of rice(Oryza sativa). AgNPs35and AgNPs58showed surface plasmon resonance andaverage sizes of 30 and 60 nm, respectively. Both AgNPs presented sphericalshape and the FTIR analysis confirmed the presence of functional groups suchas free amines and hydroxyls of biomolecules bounded to the external layer ofthe nanoparticles. Both AgNPs inhibited the growth of the three phytopatho-gens tested, andA. alternatewas the most sensible (MIC≤4 μM). Moreover,the AgNPs35and AgNPs58did not induce phytotoxic effects on thegermination and development of rice seedlings. In conclusion, these AgNPsare promising candidates to biocontrol of these phytopathogens withoutendangering rice plantsinfo:eu-repo/semantics/publishedVersio

Microbial fuel cell-induced production of fungal laccase to degrade the anthraquinone dye Remazol Brilliant Blue R

The anthraquinone dye Remazol Brilliant Blue R is largely used in the textile industry. However, its removal from wastewaters is costly and complex. Many methods have been tested to solve this ecological problem, but there is still a need for efficient methods. We propose here an alternative use of a two-chambered microbial fuel cell (MFC), fuelled with domestic wastewater in the anodic chamber, to degrade a simulated textile dye effluent made of Remazol Brilliant Blue R inoculated with an immobilised fungal strain, Pleurotus ostreatus URM 4809, as a laccase producer, in the cathodic chamber. The MFC showed continuous synthesis of laccase in the cathodic chamber, which, in turn, promoted the rapid decolourisation, of more than 86\% of the textile dye effluent. The yield was further increased by the addition of glycerol. Electrochemical monitoring also indicated an increase in power density and current density. After 20 days of MFC operation, 62.1\\% of organic matter was removed in the anodic compartment, thus leaving the effluent with a much lower toxicity.Authors would like to acknowledge the technician and fnancial support of Programa Novos Talentos provided by the Instituto de Pesquisa Tecnológica do Estado de São Paulo (IPT) and Instituto de Estudos Avançados do Mar (IEAMar).info:eu-repo/semantics/publishedVersio